Conventional heat assisted magnetic recording (HAMR) utilizes a laser in a conjunction with magnetic recording technology to write to magnetic media in a disk drive. Light is provided from a laser to a waveguide in a HAMR writer fabricated on a slider. The waveguide may be an interference waveguide (IWG) which includes multiple arms. The light travels through the waveguide toward the ABS and is split between the arms of the waveguide. The light is recombined in proximity to a near-field transducer (NFT). Light from the waveguide is coupled in to the NFT. The NFT couples light into the media at a spot size smaller than the optical diffraction limit, heating a region of the media. Coils in the apparatus energize the main pole to magnetically write to a portion of the media heated by the spot size at a relatively modest field. Thus, data may be written to the media.
In order for HAMR writers to function as desired, not only is sufficient energy required to be delivered to heat the media, but the functioning of various components desired to be monitored. For example, the waveguide may be desired to be tapped in order to monitor the power from the laser that is delivered to the waveguide. Tapping typically involves placing a tapping waveguide in proximity to the waveguide. A small amount of energy is coupled out of the waveguide to the tapping waveguide. Particularly as the HAMR transducer is scaled to smaller sizes, the fabrication and, therefore, reliable operation of such optical components may become challenging. Accordingly, what is needed is a mechanism for improving performance and fabrication of the optical components in HAMR magnetic recording.